[Lawcom]

This sounds like it should be a content rich site and there is no easy solutions to producing the goods...

You want members you want sign ups and you have to offer information that is breaking and relevant ... the business sector is hardnosed and there are companies out there already delivering ...

I would think as has been suggested email and newsletter and rss feed campaigns must be essential, which although in the short term may not stack up for you, in the mid to long term that would seem like your best options ...

You don't have to dive in, you can do it inhouse for a while before it becomes overwhelming and you have enough unique members to let it grow..

Either way it is a full time commitment and no real easy options in this sector... IMO